In recent years, a semiconductor device prepared with silicon carbide (SiC) (hereinafter, referred to as “a silicon carbide semiconductor device”) has been attracting attention as a next-generation semiconductor device with which high withstand voltage and low loss can be realized. Since the dielectric breakdown electric field strength of SiC is about 10 times as compared with silicon (Si) which has been used for a conventional semiconductor device, in particular, the silicon carbide semiconductor device has been expected to be applied to power semiconductor devices of high withstand voltage.
With regard to the silicon carbide semiconductor device, for the purpose of attaining further enhancement in withstand voltage, it has been known that, by providing a so-called terminal end region within an N type silicon carbide semiconductor layer with a P type guard ring region (terminal end well region), the electric field at the time of being applied with reverse voltage by a depletion layer, which is formed by a PN junction of the silicon carbide semiconductor layer and the guard ring region, is relaxed (for example, Patent Document 1). Moreover, in a Schottky barrier diode composed of SiC (SiC-SBD) described in Patent Document 1, a field insulation film is provided on a silicon carbide semiconductor layer in a terminal end region, and the outer peripheral end of a surface electrode is formed so as to run on the field insulation film.
On the other hand, with regard to an SiC-SBD, there are cases where an etching residue is formed at the outer peripheral end of a Schottky electrode (a first surface electrode), which is provided on the silicon carbide semiconductor layer and the field insulation film, and there is a fear that failures of the silicon carbide semiconductor device are caused because electric field concentration occurs around an etching residue when the etching residue is formed. On that account, it has been known that, by covering the outer peripheral end of a Schottky electrode with an electrode pad (a second surface electrode), which is provided on the Schottky electrode, failures of the silicon carbide semiconductor device are suppressed (see, for example, Patent Document 2) because an etching residue formed at the outer peripheral end of a Schottky electrode is not exposed.